Café Royal Cocktail Book by W. J. Tarling (1937, p.214)

2 dashesAngostura bitters — Angostura Bittersbase
0.33 partbrandy — Brandybase
0.67 partdry vermouth — French Vermouthmodifier
2 dashessyrup — Syrupsweetener
  1. Mix and strain into cocktail glass.